Chain-stitch sewing-machine.



G. E. MOLYNEUX. CHAIN STITCH SEWING MACHlNE.

1,151,528 APPLICATION FILED APR.30, I908. Patented Aug. 24:,

2 SHEETSSHEET I.

VVYINESSES:

coLuMnm PLANOGRAIH co. WASHINGTON. n c,

G. E. MOLYNEUX.

CHAIN STITCH SEWING MACHINE.

APPLICATION FILED APR.30,1908.

Patented Aug. 24, 191 5.

2 SHEETSSHEET 2.

UMTED 8TATE8 ra rnnr oration enonen n. MOLYNEUX, or ELIZABETH, NEW JERSEY, Assie von TO THE SINGER MANUFACTURING COMPANY, A CORPORATION on NEW JERSEY.

CHAIN-STITCH SEWING-MACHINE.

Specification of Letters Patent. Patented Aug, 24, 1915,

Application filed April 30, 1908. Serial No. 430,067.

To all whom it may concern Be it known that I, GEORGE E. MoLY- :vnux, a citizen of the United States, residing at Elizabeth, in thecounty of Union and State of New Jersey, have invented certain new and useful Improvements in Chain-Stitch Sewing-Machines, of which the following is a specification, reference being had therein to. the accompanying drawings.

This invention relates to an improvement in sewing machines adapted-to produce chain-stitch seams, and it consists in the improvements in the loopei '-actuating mech anism herein shown and described.

In the accompanying drawings, Figure 1 is a side elevation, partly in section, of a post sewing machine embodying the present invention in its preferred form, and Fig. 2 a front end view of thesame with the post and thebed in section and with the face-plate removed. Fig. 3 is an end elevation and Fig. 4 a side elevation of portions of the post, containing a slightly modified formof looper mechanism, and Fig. 5 a detached end view, partly in section, of the feed actuating mechanism. Fig. 6 is an end elevation and Fig. 7 a side ele vation of portions of the post containing another slightly modified form of the looper mechanism, and Fig. 8 a detached sectional view showing a portion of the side wall of the post with the fulcrum-stud for the looper-supporting bar represented in Fig. 7.

As shown in Figs. 1 and, 2, the frame of the machine is constructed with a hollow base member 1 and tubular upright member apart correspondingly with the grooves 16 of the pulley 15, such belt embracing. a simivlarly'grooved pulley 19 secured upon the rearward end of the lower rotary shaft 20. Theshaft 20 carries at its forward end the feed-actuating and lifting eccentrics 21 and respectively, the looper deflecting eccentric 23 and the ball-crank 2 1 for communicating to the looper its loop-seizing and loop shedcling movements.

The looper is shown herein of the thread carrying type with a blade 25 having the usual thread-receiving eyes and intermediate thread groove, and the shank 26 secured within a socket in the carrier '27 loosely mounted upon the tilting looper supporting bar 28 between fixed collars 29 and adopted to oscillate thereon. The loopercarrier is provided with a ball-stud 30 embraced by a strap at the upper end of the pitman 31 whose lower end is also provided with a strap which embraces the ball-crank 24 carried by the lower shaft 20, and which imparts to the looper its loop-seizing and loop-shedding movements.

The, post 1 is provided upon one side with an inwardly extending hollow boss 32 in which is .pivotally secured by means of the fulcrum-pin 33 one end of the loopersupporting bar 28, whose opposite end is flattened and is embraced by the spaced parallel guide-ribs 34 upon the inner wall of the post opposite the boss 32. The flatadjacent to the throat-plate upon the looppresenting side of the needle in its advance to seize the needle-thread loop and upon ce'edi n g needle-thrust,-

the opposite side of the needle-path materially lowerinits retrograde or loop-shedding movement.

The present looper movement, as thus described, provides for the seizure of the needle thread loops at the highest position possible so as to permit "of theem'p loyment of a short needle and'correspondingly short needle-stroke, While the dip of the looper in its retrograde or loop-shedding movement' i at the opposite side of the needle-path pro -V 'videsample clearance betvveenthe throat I plate and the looper-blade for the; thread.

loopsembracing the looper-blade and in "sures' such an angular 'lead o f the'th-read loops to the ne'edle-hole of the'throat-plate ivill 'insure againstthe premature shift-- in-g 'of the thread-loops along the looper- 'bla'de,-[ thereby insuring' th'e drawingback of such thread-loops clear of "the needle-c path "in the retreat of" the looper to avoid penetration of the needle-point in the/suc- Bv mounting' the looper-carrier intermethe looper-bar fulcrum to be comparatively little anected in its action'b'y the needle avoidingmovements, either sidewise or end- Wis'e', thus reducingto a minimum the op- V 'erative movements E of the needle-carrier rocking mechanism.

Op osed to the 'press er-foo't- 39 is the usual 'serrated feed-dog 40 mounted upon the up per end "of' the substantially vertical feedbar 41"loosfely fitted'to slide Within the ful- 'crumblocli'42 which is'secured forosc'illationup'on the boss 43 on one side of the inner Wall of the post foy means of the screw 44. As represented moreparticularly in Fig."'5','the "feed b'ar 41 is providedat its lower end with a substantially vertical-yoke 4'5 embracing'the feed actuatingi eccentric '21- inclosed at the lower end by 1 means of a I cross-bar 46. Tojthe rearward side of'the ,cro'ss-bar'46 is secured by means of screws 47 an offset" horizontally arranged yoke 48 embracing the feed-lifting eccentricf 22', upon theshaft 20.

As'willbe' readily observed,th'e eccentric,

I 22 communicatesthrough theyoke 48 the feedibar "41, While theecc'entricQl imparts usual" rising and falling movements to v the to the feed-bar throughvthe yoke 45 lateral movements Which are reversed through the action of, the fulcrum-block in giving the feeddog 40 its lateral or feedinginovements.

' "'As' represented herein, the feed-actuating eccentric 21 is movably mounted upon the fixed collar 49 havingtheadj'usting screw 50'.

controlled by the spring-retracted turning implement 51 substantially in the United States Patent to Martin Hemleb, No.

809,945, of January '16, 1906. 'llhe throw of the feed-dog is therefore adjusted by vary-' ing the relation of the eccentric 21 to the supporting shaft 20. I

,The thread handling devicesauxiliary to the needles and looper which are not specifistruction. i v v l 7 As represented in the drawings, the looper is'inretract'ed position andthe outer end of the looper-bar elevated to throw the looper-c blade in advanceof theneedlepath; the

"shafts 4 "20' revolve, the needle rises to present its loop and the point of the looper enters the loop, the outer'end of 'the bar 28 gradually descending to give'thelooper its needle avoiding movement as the pointer the needle rises abo've the looper' path. -As the needle reaches-its highest point, the take-up member52 commonly carried by the needle-barceases to act, but the continued downward movement or the bar 28-causes the looper; not only to cross the needle-path "hutfto descend slightly beneath the' throatplate '53'SQ'ELS. to tighten the needle-thread .cally essentialsof the present invention, are p or may be of any approved style orconloops 'uponthe 1oo er-blade,*which is desir-' I able especially in i'nachin'es' wherein a looper 1 similarly engage's the loops of two needles. As the'looper is retracted, it carries the taut needlethreadi loops backwardly to deflect them from the paths of their respective needles preparatory to the'descent of thelatter,

after which the riseof the loopers' bythe up- "Wardtiltin'g of the supporting bar 28 slackens pthe needle-thread loops and facilitates the release of such loops preparatory to the advance of the looper for a succeeding loop seizing operation. e I

The looper. blade,'; and particularly the lower edge thereof, is in practice so shaped as to producea slight drag upon the needlethread loops hanging upon the same during its return to initial position. i By the em- 'ploymentoi' a' risingand falling looper the I looper 'p'ointisenabled to follow the needle in its up stroketo the highest possible position beneath the throat plate, whereby a comparatively shortneedle'is adapted to bev used, whlch s a very lmportant feature in sewingmachines designed to operate at high s'pee ds,Wh1le the descent-0tthe' looper dur- 111g 1ts' advance movement causes its heel to be sufficiently loweredin its'advanceposition 'to'bring the lead of the needlethread loops rmm the throatplate under, the feeddog. to establish the [best conditions for proper handling of the threads. A's Will'be observed, the dip of the looper is described in producing the lateral needle -avoiding movement causes the inclinationof the flat 'looperfl blade to "the needle-path during the retraction of the looper and descent of the needle, whereby the looper-blade is caused to perform the additional function of a needleguard as the needles descend to enter the looper-loop.

neferring to Figs. 3 and 4, the several operative parts Within the post are substan-.

tially the same, as already described, eX- cepting the looper supporting bar 28 and its supporting and tilting means. In this form of the improvement, the looper-bar 28 is flattened at the opposite ends, and each is embraced by the forked head 36 of a pitman-rod 37, these pitmen rods having straps 38 embracing the oppositely arranged eccentrics 23 mounted upon the main-shaft intermediate the feed-actuating eccentric 21 and the looper oscillating ballcrank 2%. Each of the flattened opposite ends of the looper-supporting bar 28 is embraced by a pair of spaced parallel guideribs 34 upon the inner wall of the post, the ends of the rod 28 Working in contact with curved seats 34 intermediate said guideribs to maintain the lateral position of the looper-supporting bar. As will be observed, the bar 28 is pivotally supported by the two pitmen 3?,whose reciprocal movements cause the tilting of the bar to impart the needle avoiding movements to the needle, as described in connection with the form of the invention represented in Figs. 1 and 2.

In the form of the present improvement shown in Figs. 6, 7 and 8, the inner wall of the casing is provided with afulcrum-stud 55% carrying a conical headed screw-pin 55 upon which is mounted the looper-supporting-bar 28 with the looper carrier mounted upon one end portion and having the other end portion flattened and embraced by the forked head 36 of the pitinan rod 37 Whose opposite endis provided with the strap 88 embracing the eccentric 23 upon the shaft 20, as in the form of the improvement represented in Figs. 1 and 2. The needle avoiding movements in this ,forin of the looper mechanism are produced in practically the same manner as in the preferred form previously described, and the loop-seizing and loop-shedding looper movements are imparted in precisely the'sanie manner as in the other forms before described.

In each embodiment of the improvement herein represented; the looper-supporting bar is mounted upon a fulcrum disposed beneath the throat-plate, and thus upon the farther side of the work-supporting member relative to the direction of thrust of the needle, and means are provided for confining the looper upon this supportingbar a fixed distance from said fulcrum in all of the latters varying angular relations with the needle-path.

It will be seen from the foregoing description that in the several forms of the present improvement disclosed herein the axisof oscillation of the looper is in substantially intersecting relation with the aXis of move-- 1 ment of-the tilting looper-supporting bar,

which assumes an inclination to the path of reciprocation of the needle in one direction only never tilting from one extreme position into a position beyond perpendicular relation With the vertical needle path. In

the preferred, form of the improvement represented in Fig. 1, the fulcrum-pin 33 .is offset from the circular path in which the looper-blade oscillates a distance greater than its radius of circular movement,

7 whereby the tilting of the bar 28 to produce the sidewise or needle-avoiding movements insures the substantial rise andfall of the looper-blade as before described.

It has been common heretofore to mount thelooper for oscillation upon a supporting pin carried by a rocking frame, fulcruined beneath and at right angles to saldpin but in such manner that the movements of saidframe shifted the looper bodily from one to the other side of the needle-path without producing the substantialrising and falling movements which the present improvement is designed to impart. Accordingto' the present invention, the looperis so mounted that the means whereby its sidewise movements are imparted necessarily produces its above-describedv risingand falling movements. The looper-supporting ,bar is thus tilted by a direct connection with its operating means independent of the looper reciprocating mechanism in a range of move ment with extreme positions within a quadrant which-is limited at one, side by a line coincident with or parallel to the needlepath, so that its relation with the'latter never exceeds a right angle therewith.

As will be observed'by reference to Figs. 1 and 2, the post is constructed separately from the base portion 10f the frame, and is detachably secured upon a seat provided on the latterby means of screws 56 and dowel pins 5'21. The object of this construction is left threaded screws may be unscrewed from the fittings at their opposite ends; suitable openings being provided in practice for ac cess to such parts.

YVhile the looper-carrier is shown and described herein as loosely mounted upon the 7 and -shedding movements to the looper,

means also connected with the lower shaft for imparting to the looper-supporting bar tilting movements at varying angles to the needle-path not exceeding a rightnngle, whereby the looper-blade is given sidevvise and substantial rising and falling move ments, and guiding means upon the side of said post and adapted to engage the end of the looper supporting bar for steadying the 10 Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C. 

